/* Header Layout */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(10, 15, 28, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

/* Logo */
.logo {
  font-family: var(--font-sans);
  font-size: var(--text-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--duration-fast) var(--ease-default);
}

.logo:hover {
  color: var(--color-primary);
}

/* Navigation */
.main-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  display: block;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  padding: var(--space-2) 0;
  transition: color var(--duration-fast) var(--ease-default);
  position: relative;
}

.nav-list a:hover,
.nav-list a:focus {
  color: var(--color-text);
}

.nav-list a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: width var(--duration-normal) var(--ease-default);
}

.nav-list a:hover::after,
.nav-list a:focus::after {
  width: 100%;
}

/* CTA Button in Nav */
.nav-cta {
  background-color: var(--color-primary);
  color: white !important;
  padding: var(--space-2) var(--space-5) !important;
  border-radius: var(--radius-lg);
  font-weight: var(--font-weight-semibold) !important;
  margin-left: var(--space-4);
}

.nav-cta::after {
  display: none !important;
}

.nav-cta:hover {
  background-color: var(--color-primary-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-1px);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color var(--duration-fast) var(--ease-default);
}

.mobile-menu-toggle:hover {
  border-color: var(--color-text-muted);
}

.mobile-menu-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.hamburger {
  display: block;
  width: 1.25rem;
  height: 2px;
  background-color: var(--color-text);
  position: relative;
  transition: background-color var(--duration-normal) var(--ease-default);
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--duration-normal) var(--ease-default);
}

.hamburger::before { top: -6px; }
.hamburger::after { top: 6px; }

/* Hamburger Animation */
.mobile-menu-toggle[aria-expanded="true"] .hamburger {
  background-color: transparent;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::before {
  top: 0;
  transform: rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::after {
  top: 0;
  transform: rotate(-45deg);
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }
  
  .nav-list {
    position: fixed;
    top: 4rem;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-surface);
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-6);
    gap: var(--space-2);
    border-top: 1px solid var(--color-border);
    visibility: hidden;
    opacity: 0;
    transform: translateX(100%);
    transition: transform var(--duration-normal) var(--ease-default),
                opacity var(--duration-normal) var(--ease-default),
                visibility var(--duration-normal);
  }
  
  .nav-list.is-open {
    visibility: visible;
    opacity: 1;
    transform: translateX(0);
    height: calc(100vh - 4rem);
  }
  
  .nav-list li {
    width: 100%;
    border-bottom: 1px solid var(--color-border);
  }
  
  .nav-list a {
    font-size: var(--text-lg);
    padding: var(--space-4) 0;
    width: 100%;
  }
  
  .nav-list a::after {
    display: none;
  }
  
  .nav-cta {
    margin-top: var(--space-4);
    margin-left: 0;
    text-align: center;
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .nav-list,
  .hamburger,
  .hamburger::before,
  .hamburger::after {
    transition: none;
  }
}